Ask Kirsten Weiss: Dealing with Scope Parallax Error

Uncommonsense asks the next Annie Oakley (Kirsten Weiss above) about something technical to do with rifles and scopes and stuff.

I recently purchased a laser bore sighter. While experimenting, I was stunned at how much parallax error I could see in my rifle scopes when looking at a target just 15 yards away. What do you do to mitigate parallax error?

Ms. Weiss replies “Uncommon Sense, I don’t want to assume. Do you have a knob on your scope for Parallax adjustment? [ED: really?] If your scope doesn’t have one there’s an easy fix. In fact, a lot of times I use this method even when my scope DOES have parallax adjustment . . .”

Why? If you don’t know the exact size of something, people tend to compare it with something established or otherwise easy to gauge. Head sized target- I’d guess ~7-8 inches. The man didn’t do anything illegal. Chill.

I don’t know what she means by “parallax knob,” but it sounds to me like the scope’s elevation adjuster knob. If so, I (and probably most of us) are doing the same thing by another name.

My .22 has a scope set so that the laser boresight and scope cross hairs coincide at 25 yards. This means that at 25 yards, the bullet passes through the target on the rising leg of its trajectory.

It hits peak elevation above the line of (scope) sight at some unknown distance. At 50 yards it strikes an inch or two above the line of sight. Beyond this, it drops back through the line of sight and is 5 inches low at 100 yards.